static int ai_writeTripleFile(Collection<TripleWeb> triples, OutputStream out) ctex {
  print("Writing triple file");
  new L<S> names;
  new Map<S, Int> index;
  ai_writeTripleFile_precollectNames(names, index, triples);
  new ByteArrayOutputStream baos;
  PrintWriter writer = utf8printWriter(baos);
  int n = 0;
  for (TripleWeb w : triples) {
    ++n;
    S title = null;
    S moreInfo = quote(str(w.globalID())) + " " + quote(unnull(title)) + " " + quote(unnull(w.source())) + " " + (w.unverified() ? "u" : "v") + " " + w.created();
    O result = w.result();
    if (result != null)
      moreInfo += " (" + sfu(result) + ")";
    
    writer.write(
      ai_writeTripleFile_indexGet(names, index, w.a) + " " +
      ai_writeTripleFile_indexGet(names, index, w.b) + " " +
      ai_writeTripleFile_indexGet(names, index, w.c) + " " + moreInfo + "\n");
  }
  writer.flush();
  //out.println(struct(names));
  print("Have " + n2(names, "name") + ", " + toM(baos.size()) + "M buffered bytes");
  PrintWriter writer2 = utf8printWriter(out);
  for (S s : names)
    writer2.println(quoteUnlessIdentifierOrInteger(s));
  writer2.println();
  writer2.flush();
  baos.writeTo(out);
  ret n;
}

static int ai_writeTripleFile_indexGet(L<S> names, Map<S, Int> index, S s) {
  Int i = index.get(s);
  if (i == null) {
    i = l(names);
    names.add(s);
    index.put(s, i);
  }
  ret i;
}

static void ai_writeTripleFile_precollectNames(L<S> names, Map<S, Int> index, Collection<TripleWeb> triples) {
  for (TripleWeb w : triples) {
    ai_writeTripleFile_indexGet(names, index, w.a);
    ai_writeTripleFile_indexGet(names, index, w.b);
    ai_writeTripleFile_indexGet(names, index, w.c);
  }
  sortInPlaceIC(names);
  index.clear();
  for i over names: index.put(names.get(i), i);
}

Began life as a copy of #1011763